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  1. #1
    Join Date
    Feb 2014
    Posts
    4,492

    LSA versus LS9 Blower

    Was just reading in another post about modding the LSA to "keep up" with the LS9 etc.

    I've actually spoken to several well known US tuners about the LS9 versus the LSA blower.

    In the stock production format the LS9 does make 638HP and the LSA makes 585HP.
    GM built the LS9 for the ZR1 Corvette before they built the LSA engine and at the time GM had a written rule that no GM made car was allowed to be faster or more powerful than their hero model "the corvette".
    (This rule was recently abolished when the LT4 went into the CTS-V)

    Anyway during building of the LSA engine it was found that the LSA 1900 blower makes nearly or almost exactly the same stock production HP output as the LS9 2300 blower.

    Sandbagging the engine via camshaft
    This is evident by reducing the LSA power output via the camshaft. As we know holding the valve open longer and giving it larger lift allows more air into and out of the engine.

    LSA camshaft:
    Duration 198 intake / 216 exhaust
    Lift .492 intake / .480 exhaust

    LS9 camshaft:
    Duration 211 intake / 230 exhaust
    Lift .562 intake / .558 exhaust


    The power output difference:
    The HP difference in the stock LSA versus LS9 SAE rated HP is 53HP, it's been proven many times over in the aftermarket arena that guys swapping the LSA camshaft for the LS9 camshaft are seeing 40rwhp gains and that gain is generally on a "tuned" LSA hence pretty much making up the 53 engine HP difference.


    One tuners perspective:
    Speaking to a well known US tuner who mentioned a LS9 blower running at 20psi of boost and an LSA blower running at 16psi of boost, both with the same heads and camshaft and both tuned by the same tuner.

    He noted that the LS9 blower showed less air was passing the MAF in comparison to the LSA blower, showing that the LS9 blower is sucking in less air and is more restrictive since showing a higher boost pressure (psi restriction) and that being that it was at a higher pulley combination resulting in more boost pressure you would have thought it would be sucking in more air.

    Then we spoke about the cooling system of the LS9 blower and the intake temps shown, which also showed that the LS9 blower runs hotter, this comment about the heat has also been said by many guys in the US already.

    Taking the conversion even further into the rotor pack the comment came up which was the only difference is the blower rotors are longer in the 2300 giving the air a touch more time for compressing the air, however he felt this touch more length probably was not worth much and that larger diameter rotors would have worked better.

    Giving example to this is a guy in the US running 9.8sec blower only with a ZL1 LSA who then swapped to the heartbeat to find he only picked up 10rwhp at peak and is still running 9.8sec in the 1/4 mile tuned by a very well known workshop.


    This then turned my attention to this same topic on many of the US forums where plenty of people are finding similar results and the general consensus is that the LSA blower is a better blower than the LS9.

    Low down torque:
    Guys have also found that the LSA blower can make more low down torque than the 2300 blowers due to the fact it has less rotational mass being that the rotor pack is not as long and is lighter to spin up at a quicker rate of speed. Meaning you can take off faster with a 1900 blower since it gets going quicker.

    In my eyes from the information I have found the LSA blower is the perfect sized blower for our 6.2L engines, given you can pick up an LSA crate motor for around 10-12k it kills the heartbeat which inherently has it's own issues.

    What would be highly interesting is if the heartbeat were to be made in a 1900 format instead of 2300 and if the heartbeat had a 3rd intercooler brick placed over the rotor pack to reduce even more heat and to stop the issues found with the thin lid cracking under high heat/boost.

    A 1900 Heartbeat may then be the perfect sized blower for a 6.2L engine....however as said a crate LSA (whole engine) is 10-12k and a heartbeat is 12-13k it's a pretty easy decision if you want to put a blower on your car buy the whole damn engine.


    I hope this information may help some of you guys out there and when you line up next to the new GTS-R and your are both modded similarly it will be an almighty close race.

    PS I would still love to own a GTS-R but the purists wouldn't like me owning one...LOL

    2014 HSV GenF-GTS fitted with a Forced Induction Interchiller
    http://www.facebook.com/ForcedInductionInterchillers
    Australia's outright Fastest VF GTS & Fastest 6.2L 1900LSA with a stock bottom end
    9.700 @145.22mph 21/June/2017
    V-Box Results 0-100km/h in 2.47sec

    Looking for colder IAT's? we have achieved 11c IAT2 on a 41c day and -8c during winter.
    We have proven cabin AC vent temps are better than GM spec, both IAT2's and vent temps are all on video with nothing to hide.

  2. #2
    Join Date
    Apr 2013
    Location
    Melbourne
    Posts
    1,313
    So the heartbeat is still the better blower, as it gained 10whp on the same car?

    Who holds the better IAT2's in stock form (i.e. no interchiller) say using LS3 and LSA, both being 6.2L?

    Surprised to hear your thoughts regarding the 1.9L (LSA) out performing the 2.3L (LS9)

    Racing... Because football, rugby, basketball & golf only require one ball

  3. #3
    Join Date
    Feb 2014
    Posts
    4,492
    Quote Originally Posted by Nath View Post
    So the heartbeat is still the better blower, as it gained 10whp on the same car?

    Who holds the better IAT2's in stock form (i.e. no interchiller) say using LS3 and LSA, both being 6.2L?

    Surprised to hear your thoughts regarding the 1.9L (LSA) out performing the 2.3L (LS9)
    Well yes and no to your first question Nath the 2300 heartbeat is suppose to push in 21% more air 1.9L + 21% = 2.3L
    Yet you are not seeing those gains equal out very well now are you for 21% more air entering the engine?
    Purpose the question in this manner; Hey LSA blower if I gave you 21% more air how much more HP do you think you can make?

    10HP at peak is not really worth much, if it were 10rwhp throughout the entire power curve it would be a different story.
    And selling the heartbeat on the basis of "if you want to upgrade from your 1900 blower to a bigger better blower"....well 12k isn't worth 10rwhp at peak either.

    Which then brings full circle back to the statement of how can making the rotors longer give you 21% more air?
    And as above the MAF doesn't lie it measures how much air is entering the engine, if it says less air is entering the engine on an LS9 2300 at 20psi of boost versus a LSA 1900 at 16psi of boost then there is less air entering the engine.

    Next the fact with the 2300 you are losing low down HP and torque to get you off the line where the 1900 is already off and running the 2300 is trying to gain back ground now.

    The heartbeat as a better intercooler system, purely based on the fact that the intercooler bricks are about 4x the size of the LSA blower. So there is a larger surface area for heat transfer. However in saying that it does need a 3rd intercooler brick similar to what callaway have now done see here:



    This would also solve the lid cracking issue on the heartbeat since all of the 165c rotor heat is being thrown directly into the top lid of the blower and weakening it.

    As said before it would be a very interesting blower to make a 1900 heartbeat with 3 intercooler bricks.
    However as also said....the price 12k for a heartbeat or 10-12k for a WHOLE LSA engine!
    Last edited by GenF-GTS; 28-10-2016 at 04:28 PM.

    2014 HSV GenF-GTS fitted with a Forced Induction Interchiller
    http://www.facebook.com/ForcedInductionInterchillers
    Australia's outright Fastest VF GTS & Fastest 6.2L 1900LSA with a stock bottom end
    9.700 @145.22mph 21/June/2017
    V-Box Results 0-100km/h in 2.47sec

    Looking for colder IAT's? we have achieved 11c IAT2 on a 41c day and -8c during winter.
    We have proven cabin AC vent temps are better than GM spec, both IAT2's and vent temps are all on video with nothing to hide.

  4. #4
    Join Date
    Jan 2015
    Posts
    185
    Very interesting and well timed post GenF.
    Having been chatting with a mate about next round of mods for our GTS's.
    Possibilities we have discussed include:
    Bigger s/c
    strokers
    forged internals
    and the list does on..

    Many have said our lil' 1900 blower is great plus not many suppliers support the bigger blower is a better blower sales pitch with any actual numbers (ie. whipple, harrop etc..)
    Thanks again for the good info

  5. #5
    Join Date
    Feb 2014
    Posts
    4,492
    I think Active Automotive's dyno and track results even reflect the "perfect" sizing of the LSA 1900 blower.

    They made 736.7rwhp with the LSA (Green Line)
    And 832rwhp with the 2.9L whipple (Red Line)

    Now the rotors on the whipple are bigger in size but brings back into question more rotational mass.

    The LSA blower on this dyno is showing roughly 600rwhp at 4000rpm and the whipple only 390rwhp thats a massive 210rwhp win to the LSA blower.

    Not only that it's not until 5500rpm that the whipple actually starts to make more HP and TQ than the LSA blower.



    With the correct tire combo, more tuning on the LSA blower it could easily beat the whipple at the track and it nearly did, the whipple went 9.8 on a different day and the LSA went 9.9...hell maybe if they had the exact same track conditions they would have both run 9.8sec.

    Now put yourself in the shoes of owning a GTS already fitted with an LSA blower and you spend what 15k and thats the only result you get from it?....hardly worth it.

    The LSA blower is perfectly suited to this sized engine, it's not a dyno queen blower but it is a bloody fast one at the track.
    Last edited by GenF-GTS; 20-12-2016 at 11:35 PM.

    2014 HSV GenF-GTS fitted with a Forced Induction Interchiller
    http://www.facebook.com/ForcedInductionInterchillers
    Australia's outright Fastest VF GTS & Fastest 6.2L 1900LSA with a stock bottom end
    9.700 @145.22mph 21/June/2017
    V-Box Results 0-100km/h in 2.47sec

    Looking for colder IAT's? we have achieved 11c IAT2 on a 41c day and -8c during winter.
    We have proven cabin AC vent temps are better than GM spec, both IAT2's and vent temps are all on video with nothing to hide.







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